background worker progress changed

Hi,

I'm having trouble getting the string from progress changed in bgw.

Well, when i type the following code it works:

HTML Code:

---

msgbox(e.userstate)

---

In this case i get the progress changed (string value)

But if i write in progresschanged :

HTML Code:

---

text1.text=e.userstate.tostring

---

i get nothing...

this is how i send data to reportprogress:

HTML Code:

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WorkerL.ReportProgress(10, "string")

---

Any ideas?


Cheers!

bump? :(

I created this simple test and it works as advertised.

Code:

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    Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        BackgroundWorker1.ReportProgress(10, "string")
    End Sub

    Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
        TextBox1.Text = DirectCast(e.UserState, String)
    End Sub

---

The UserState is an object.

Is you code ever calling the WorkerL.ReportProgress(10, "string") portion of your code? Set a breakpoint on that line and see if it ever hits it.

You might need to provide more details of how your code works. From what you posted it looks like it should work but obviously you are missing something if its not, but i cant tell from what information you provided.

Thanks for the reply...

This is what i do:

start worker and calling a function in _DoWork ... that same function reports progress to the worker...which gets the reported progress and shows it in a message box but it wont show it in text box or any other form :/

So, if i put in ProgressChanged something like :

Quote:

---

msgbox (e.userstate)

---

i will get the the reported string ....

otherwise it wont work...i really don't know why

Quote:

---

Originally Posted by batori

Thanks for the reply...

This is what i do:

start worker and calling a function in _DoWork ... that same function reports progress to the worker...which gets the reported progress and shows it in a message box but it wont show it in text box or any other form :/

So, if i put in ProgressChanged something like :


i will get the the reported string ....

otherwise it wont work...i really don't know why

---

What? Dowork calls a function that reports progress? I am confused.

Ok, let me explain in a better way.

So,

Code:

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Private Sub WorkerL_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles WorkerL.DoWork

      CALCULATE_NUMBERS(selected_numbers)
    End Sub

---

Code:

---

Private Sub WorkerL_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles WorkerL.ProgressChanged
    ' this code works, shows the state (string)
        MsgBox(e.UserState)
  'this code below returns nothing
        txtDebug.Text = DirectCast(e.UserState, String)

    End Sub

---

Code:

---

Public Function CALCULATE_NUMBERS(num as integer)
' Do some work
frmMain.WorkerL.ReportProgress(10, "string")
End Fucntion

---

Have you actually set WorkerReportsProgress to true?

You do realize your not actually reporting any progress.

Using the BackgroundWorker Component

Yes, of course it is.

I'm even getting a message box when progress is "triggered" ... it's just that i cant get that userstate to a textbox or label...i can only get it in a message box form...isn't that strange??

:(

I don't think we are seeing the whole picture here, but just for grins as giggles, try replacing the code in the progress handler with this:

Code:

---

      If InvokeRequired Then
        MsgBox("Progress from wrong thread")
        Me.Invoke(New Action(Of Object, System.ComponentModel.ProgressChangedEventArgs)(AddressOf WorkerL_ProgressChanged), New Object() {sender, e})
      Else
        Text1.Text = e.UserState.ToString
      End If

---

and let us know what happens.

Quote:

---

Originally Posted by batori

Ok, let me explain in a better way.

So,

Code:

---

Private Sub WorkerL_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles WorkerL.DoWork

      CALCULATE_NUMBERS(selected_numbers)
    End Sub

---

Code:

---

Private Sub WorkerL_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles WorkerL.ProgressChanged
    ' this code works, shows the state (string)
        MsgBox(e.UserState)
  'this code below returns nothing
        txtDebug.Text = DirectCast(e.UserState, String)

    End Sub

---

Code:

---

Public Function CALCULATE_NUMBERS(num as integer)
' Do some work
frmMain.WorkerL.ReportProgress(10, "string")
End Fucntion

---

---

When I run this

Code:

---

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BackgroundWorker1.WorkerReportsProgress = True
        BackgroundWorker1.RunWorkerAsync()
    End Sub

    Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        why()
    End Sub

    Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
        TextBox1.Text = DirectCast(e.UserState, String)
    End Sub

    Private Sub why()
        BackgroundWorker1.ReportProgress(10, "string")
    End Sub

---

The "string" appears in the textbox. Try removing frmMain from this frmMain.WorkerL.ReportProgress(10, "string")

I tried TnTinMN method , it did not show anything....
I tried dbasnett method , and it worked....

So , what i did, i moved the Function from being Public in the module, to being Public in frmMain and then.....it works!

But then again...when i had the function in the module, the progress did "arrive" to frmmain, and it was shown in the msgbox but not in any other textbox. label or whatsoever....but having a public function , in the frmMain code...worked.

But i still don't get it...

Quote:

---

Originally Posted by batori

I tried TnTinMN method , it did not show anything....
I tried dbasnett method , and it worked....

So , what i did, i moved the Function from being Public in the module, to being Public in frmMain and then.....it works!

But then again...when i had the function in the module, the progress did "arrive" to frmmain, and it was shown in the msgbox but not in any other textbox. label or whatsoever....but having a public function , in the frmMain code...worked.

But i still don't get it...

---

The reason is that a MODULE has global scope and simply calling frmMain is referencing the TYPE of form frmMain and not the instantiated form. I suppose if you prefixed frmMain with My.Forms.frmMain then it would work in the module but you did the right thing by moving your function to the form.

I tried your suggestion to use my.forms.frmMain...still does not work ...

i can only get the string in progresschanged by using MSGBOX .... as usual....

i still dont get it ....

Did you try
WorkerL.ReportProgress(10, "string")

yes, with both my.forms.frmmain.workerl and with frmmain.workerL...

progresschanged is triggered and msgbox return the value...but nothing else does.... ???? :/

So out of curiosity I tried this

Code:

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Public Class Form1
    Public WithEvents BackgroundWorker1 As New System.ComponentModel.BackgroundWorker

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BackgroundWorker1.WorkerReportsProgress = True
        BackgroundWorker1.RunWorkerAsync()
    End Sub

    Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Do While True
            why()
            Threading.Thread.Sleep(1000)
        Loop
    End Sub

    Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
        TextBox1.Text = DirectCast(e.UserState, String) & " " & e.ProgressPercentage.ToString
    End Sub

    Private Sub why()
        BackgroundWorker1.ReportProgress(10, DateTime.Now.ToString("HH:mm:ss.f"))
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        test()
    End Sub
End Class


Module Module1
    Public Sub test()
        Form1.BackgroundWorker1.ReportProgress(20, "TEST")
    End Sub

End Module

---

Works, but I personally don't like using the default instance.

Ok... hold on... I'm completely confused... if the process that's doing the work is in a module, that should be fine... the UI should only be updated in the ReportProgress event, which should be back on the main form... so... there shouldn't be any need to access the instance let alone the default instance...

I'm beyond a little confused here...

@Batori - It might help if you posted your ACTUAL code... not bits and pieces... but the actual code.... all of the BGW events, plus how you're starting it, how you're opening the form, and your module code that is doing the work.


-tg

Ok... I see the problem... in the sub, you need a reference to the BGW in order to call it's report process method... simple... pass it in...

Code:

---

Public Function CALCULATE_NUMBERS(num as integer, someBGW as BackGroundWorker)
' Do some work
    someBGW.ReportProgress(10, "string")
End Fucntion

---

Code:

---

Private Sub WorkerL_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles WorkerL.DoWork

      CALCULATE_NUMBERS(selected_numbers, WorkerL)
    End Sub

---

-tg

Why is the backgroundworker not located on the form any way.

Don't forget, if you are accessing a control outside of the thread it was created on you SHOULD be using a delegate to update that control!

First things first make sure the backgroundworker is correctly configured to report progress.
In the dowork event reference the background worker and call the reportprogress function.
(Percentages are calculated easily via NumberProcessed / NumberTotal * 100)
In the backgroundworker reportprogress event reference a delegate IF accessing a "foreign" control:
Example

Code:

---

Public Sub MyUpdateControlInvoke(Byval MyProperty As SomePropertyType)
        If MyControl.InvokeRequired Then
                MyControl.invoke(New MyUpdateControlDelegate(AddressOf MyUpdateControlInvoke), MyProperty)
        Else
                MyControl.Value = MyProperty
        End If
End Sub

Public Delegate Sub MyUpdateControlDelegate(Byval MyProperty As SomePropertyType)

---

You can then use this delegate to access a control no matter what thread you start by using:

Code:

---

MyUpdateControlInvoke(MyProperty)

---

Hope this makes sense :D

@ident ... it is.

@tg...i will try what you suggest! :)


EDIT:

@tg...i tried your last solution but still it did not work ... i still get the string in a msgbox but not in a textbox, label, ecc...
the first soulition has been tried to but with my function, and in that case it does the calculating but it does not give the reporting back.

@duckles ... tried your solution, adding it to module but still, did not work ...

I noticed that even if i put the following code in ProgressChanged ... it won't display it .. but again, a message box will!
I even tried to display progress percentage...still, no luck ... only a msgbox will display the progress percentage.

Code:

---

txtDebug.Text = "test"

---

Read Johns articles on managing data with multiple forms and default form instances

http://jmcilhinney.blogspot.co.uk/

We are trying to help you yet you avoid answers. Why does it need to be in a module.

Quote:

---

Originally Posted by duckles

Don't forget, if you are accessing a control outside of the thread it was created on you SHOULD be using a delegate to update that control!

First things first make sure the backgroundworker is correctly configured to report progress.
In the dowork event reference the background worker and call the reportprogress function.
(Percentages are calculated easily via NumberProcessed / NumberTotal * 100)
In the backgroundworker reportprogress event reference a delegate IF accessing a "foreign" control:
Example

Code:

---

Public Sub MyUpdateControlInvoke(Byval MyProperty As SomePropertyType)
    If MyControl.InvokeRequired Then
        MyControl.invoke(New MyUpdateControlDelegate(AddressOf MyUpdateControlInvoke), MyProperty)
    Else
        MyControl.Value = MyProperty
    End If
End Sub

Public Delegate Sub MyUpdateControlDelegate(Byval MyProperty As SomePropertyType)

---

You can then use this delegate to access a control no matter what thread you start by using:

Code:

---

MyUpdateControlInvoke(MyProperty)

---

Hope this makes sense :D

---

No. The whole point of the BGW is to make threading and delegation easy. Also there is no need to create your own custom delegate. You would never invoke like this using the BGW.

Side point since no custom delegate is needed.

vb Code:

Public Class Form1
 
    Public Sub MyUpdateControlInvoke(ByVal MyProperty As SomePropertyType)
        Me.Invoke(Sub() MyControl.Value = MyProperty)
    End Sub
 
End Class

or if you wanted to check invoke needed.

vb Code:

Public Class Form1
 
    Public Class SomePropertyType
 
    End Class
 
    Public Sub MyUpdateControlInvoke(ByVal MyProperty As SomePropertyType)
        If Me.InvokeRequired Then
            Me.Invoke(New Action(Of SomePropertyType)(AddressOf MyUpdateControlInvoke))
        Else
            ' what ever
        End If
    End Sub
 
End Class

Batori: Please clarify.

Are you trying to get a progress percentage OR are you trying to display a progress "step"?
Also:

Code:

---

    Private Sub why()
        BackgroundWorker1.ReportProgress(10, DateTime.Now.ToString("HH:mm:ss.f"))
    End Sub

---

Should be inside of the DoWork event.

Please clarify further.

Well, i'm having that function in a module because im used to have functions there and not "mess up" with my form code.

@duckles , withing your code i'm trying to get

Code:

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DateTime.Now.ToString("HH:mm:ss.f")

---

which equals

Code:

---

e.UserState

---

and i really do get that part of a code but only in a msgbox in frmMain.

..out of curiosity i tried to get in a textbox something like

Code:

---

txtDebug.text =  e.ProgressPercentage

---

and that too did not show in the textbox but only in a msgbox


i could put the function in the main form code and then it would work, as tested ... but i'm not sure why it does work "partially" when the function is stored in a module, does give results in a msgbox and not in any other txtbox, label, ecc....

@ident: how should i report then progress from a public function stored in a module when taht function is called from a background worker stored in the main form?

edit:

not even this works when put in progresschanged:

Code:

---

txtDebug.Text = txtDebug.Text & "test"

---

WHY IS IT IN A module. I guess you not bothered to read that last link i provided. Its so frustrating when im helping you and your sticking your fingers in your ears and saying "im not listening".

It doesn't really matter what the function is...

Code:

---

    Public Function CALCULATE_NUMBERS() As String
        Dim a As Integer = 0
        a = a + 1
        frmMain.WorkerL.ReportProgress(10, a)

    End Function

---

Still the same thing when the function is stored in a module. Msgbox from frmMain WorkerL progresschanged gives the result back, txtbox and others...don't.

I do get the result in a txtbox on RunWorkerCompleted but never on progresschanged.

Quote:

---

Originally Posted by batori

Well, i'm having that function in a module because im used to have functions there and not "mess up" with my form code.

---

1) put the function back in the form - there is zero reason for it to be in a module.
2) there's no reason for it to be a function, it should be a sub - it doesn't even return anything.
3) Just use bgw.ReportProgress... no need to specify the form or anything.
4) You ReportProgress event should then work.

-tg

By having the function/sub on the main form, everything works fine ....
But , still....im interested why do i get the report in a msgbox and not in any other textbox , label, ecc ... i'm frustrated

That last sentence touches on an important point and a source of confusion for some. There’s no point updating the default instance of a form class if you haven’t actually displayed the default instance of that class in the first place. This is one of the reasons I say that, if you’re going to use default instances at all, you should use them all the time. For instance, if you create a form and display it like this:


Dim myForm As New SomeForm

myForm.Show()

then you can’t then refer to the default instance of the SomeForm class and expect the form on your screen to be affected. You’ve created one instance and displayed that, then the system creates the default instance. They are two different objects so making changes to one will not affect the other. If you’re going to make changes by referring to the default instance then you need to have displayed the default instance in the first place:

ident, i really don't understand what are you saying...

Regardless, i found a solution....still, having the function stored in a module!

Here it is :

Start with a button to trigger the worker...all in a form

Code:

---

Private Sub cmdSTART_Click(sender As Object, e As EventArgs) Handles  cmdSTART.Click
        WorkerL.ReportProgress(10, CALCULATE_NUMBERS)
End Sub

Private Sub WorkerL_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles WorkerL.DoWork
  CALCULATE_NUMBERS()
End Sub

Private Sub WorkerL_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles WorkerL.ProgressChanged
        txtDebug.Text = e.UserState
End Sub

---

' function stored in module

Code:

---

  Public Function CALCULATE_NUMBERS() As String
        Dim a As Integer = 0
        a = a + 1
        CALCULATE_NUMBERS = a

 End Function

---

do you have any interest in learning?

I don't see how that could possibly work...

Wait.... oh my...

Nope.... no... not gonna do it... I'm jsut going to bite my tongue... Not going to say anything further.

-tg

does the op even look at any replys?

2) there's no reason for it to be a function, it should be a sub - it doesn't even return anything.

Don't know. No longer care. I'm unsubscribing from this thread. It's gone way too long for what should have been a simple issue with a simple fix.

-tg

100% AGREE , un scribing also

@dbasnett - Thank you for the simple and effective approach to this problem. Old threads can indeed be useful.